Stitch-forming mechanism for sewing-machines



S. G. TATE STITCH FORMING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED OCT. 8' I9I8.

1,37 1 ,652, Patented Mar. 15,1921.

3 SHEETSSHEET I.

50 snow WM S. G. TATE STITCH FORMING MECHANISM FOR SEWING MACHINES.

- APPLICATION FILED OCT. 8. 1918.

1,3? 1,652,. Pat ted Mar- 15, 1921.

3 SHEETS-SHEET 2.

, S. G. TATE.

"STITCH FORMING MECHANISM FOR SEWING MACHINES.

, APPLICATION FILED OCT. 8,1918.

1,371,652, Patented Mar. 15, 1921 3 SHEETS-SHEET 3.

v Chicago, in the county UNITED STATES PATENT OFFICE.

SAMUEL GEORGE TATE, OF CHICAGO, ILLINOIS, ASSIG-NOR TO UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

STITCH-FORMING MECHANISM FOR SEWING-MACHINES.

Specification of Letters Patent. Patented RIar. 15, 1921 Application filed October 8,- 1918. Serial No. 257,370.

To all whom it may concern Be it known that I, SAMUEL GEORGE TATE, a citizen of the United States, residing at of Cook and State of Illinois, have invented certain new and useful Improvements in Stitch-Forming Mechanisms for Sewing-Machines, of which the following is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

The invention relates -to new and useful improvements in sewing machines and more particularly to the stitch forming mechanism and the means for operating the same from the main shaft of the machine.

An object of the invention is to provide a sewing machine with a stitch forming mechanism wherein the thread joining the lines of needle stitching is formed into loops by the cooperative action of a fixed guide and a movable thread manipulating member, which thread manipulating member is .mounted to oscillate about a vertical axis and wherein said member is actuated by clirect connection to a main operating shaft extending through the standard of the machine, so as to avoid as far as possible lost motion and Wear of the-parts, and thereby increasing the efiiciency ing mechanism.

A further object of the invention is to provide a stitch forming mechanismof the above character wherein the cross thread joining the lines I of needle stitching is formed into loops .by a thread hook carried byan oscillating yoke, which yoke in turn is actuated by a direct connection tothe main operatingshaft.

- These and other objects will in part be obviousand will in part be hereinafter more 7 fully described.

In the drawings which show by way of illustration one embodiment of the invention s 3 Figure 1 is, a -vertical; sectional view through; a portion of machine having my improvement applied thereto;

Fig. 2 is a view partly in horizontal sec- 1 tion and partly inplan of the machine;

ing the fixed thread guide and the-movable said movable thread hookof the stitch forni- Fig. 3 is a detail in vertical section show- "F- g. 4 isa view partly in section and pa y in t p. pla lsh i gthe e f and the parts of-the thread laying mechanism adjacent the same, the hook being at the forward end of its stroke;

Fig. 5 is a view similar to Fig. 4, but showing the thread hook at the rear end of its stroke;

Fig. 6 is a view partly in plan and partly in front elevation, showing the needles and the thread laying mechanism adjacent the needles; and

Fig. 7 is a View showing more or less diagrammatically and on an enlarged scale, the arrangement of the cross thread relative to the lines of needle stitching, also showing the arrangement-of the needles and the hook when the hook is holding the loop in the cross thread for one of the needles to enter.

In the present embodiment of the invention the machine includes, a supporting standard 1, having a laterally projecting arm 2. Mounted in the standard and laterally projecting arm, is a cross shaft 3, which is hereinillustrated as the main shaft operated by a suitable belt wheel 4. Extending from the free end of the arm 2 is a second, arm 5, which has a depending member 6, carrying the work supporting arm proper, indicated at 7 in the drawings. This work supporting arm is suspended. so that the material to be stitched may be placed underneath the same and its edges brought together and stitched and fed off from the end of the arm, thus forming a tubular section. Located in the arm 5 is a shaft 8 which is operated from the main shaft 3. Located in the work supporting arm 7 is a suitable feeding mechanism which is actuated from devices connected with the shaft 8. Also locatedin this work supporting arm 7 and at the free end thereof, is a looper 9 which is operated by suitable devices from the shaft 8.

Cooperating with the looper as herein shown, are three needles 10, 11 and 12. These three needles are carried by a needle bar 13, which is mounted to reciprocate in bearings 1414 in the projecting arm 2. The main shaft 3 is provided with a crank to which a link 15 is connected and this link in turn is connected to a lever 16, which is connected by a link 17 to the needle bar. As the main shaft rotates, the needle bar will be reciprocated through these devices. The material is held on the work support by a presser foot 18, whichis carried by a of the fabric sections to be united, are turned up and directed to the guide slot or channel 20 and these upturned edges are trimmed by a trimming mechanism which includes a fixed blade 21 and a movable blade 22. The movable blade 22 is carried by a yoke 23 journaled to turn about a vertical axis. This yoke carries an arm 2 1 which is connected to an eccentric strap 25 cooperating with an eccentric on the main shaft 3. The trimming mechanism per 80 forms no part of the present invention, but'is shown, de-

scribed and claimed in my co-pending apph- I cation, Serial Number 257,369, filed of even date herewith. The looper 9' cooperates with all three needles, thus joining the looper thread loops on thelower face of the fabric and uniting the edges of the fabric sections which may be abutted or which may be slightly overlapped.

The fabric sections are joined on their upper face by a cross thread which is formed into loops and secured to the fabric sections by the needle threads. It is understood that the needle threads form three parallel lines of loops which together with the looper thread form parallel lines of needle stitch- The cross thread is led from a suitable source of supply through guides to a fixed thread guide 26. This fixed thread guide is formed at the lower end ofa rod 27, secured to an arm 28, projectingfrom a collar 30,

which is mounted on the presser bar 19 which carries the presser foot 18. Said collar 30 is secured to the presser bar by a set screw 32 and the rod 27 is vertically adjustable in the arm 28 and is-secured in adjusted positions by a set screw 33. These connecbeing adjusted vertically in this tion's permit the thread guide to be adjusted vertically and also in the arc of a circle about the presser bar as a center. Associated and cooperating with 7 thread guide is a movable thread hook 34:, which hasa dove tailed notch 35 in the free end thereof. The hook projects laterally from the lower end of a rod 36, which is carried by an arm 37. Said rod is capable of arm and is secured in adjusted position by a set screw 38. The arm 37 is formed integral as herein I shown with ayoke 39. The yoke consists of spaced collars 10- 10 and a connecting bar The arm 37 projects and the fixed collar 30 which carries the fixed thread guide. Projecting from the yoke is a ball stud 42. An eccentric strap 43 engages strap cocperates .withan eccentricit on the main shaft'3. As this main shaft rotates,

this fixed this ball stud and said eccentricv it will oscillate the yoke 39 and this will oscillate the thread hook 34. In Fig. 7 of the drawings, I havev shown the cross thread at 0, the needle threads at a, a and n of the needles 10, 11 and 12 respectively.

lVhen the thread hook 34 is at the rear end of its stroke, the hook is disposed adjacent the fixed thread guide as clearly'shownin Fig. 5 of the d-rawings. As the hook moves forward, it will engage this cross thread forming a loop therein, as clearly shown in Fig. 1 0f the drawings. lWhen the hook is at the extreme forward end of its stroke, the trand of the thread loop running from the fixed thread guide to the notched end 35 of the hook, lies between the needles 10 and 11 or if desired, said thread may be caused to lie between the needles 11 and 12. The other strand of the threadloop carried by the hook, extends'from the notched end of the hook to the previous interlocking of the cross thread with the needle stitches and in rear of the nedle 12, so that the'needle 12 thread in the center line of stitching.

'While'I, have shown my improved cross thread laying mechanism as used with three needles, it will be understood of course, that from certain aspects of the-invention, it may be used withtwo needles or with more than three needles. It will also be obvious that minor changes 1n the details of construction and arrangement of parts maybe made without departing from the spirit of the in vention as set forth in the appendedclaims. Having thus described my invention, what I claimas new and desire to secure by Letters Patent, is: 1. The combination of astandard, an arm projecting therefrom, a depending support carried by said arm, a'work-s'upport 'sus-' pended by said support; "and extending toward and terminating adjacent said standard, a main shaft extending through said standard and into said arm, a needle her carried by said projecting arm, a plurality of needles mounted thereon, said needle bar being disposed so asto operateat' the free end of'said work supporting'arm,'means within said arm for actuating the needle bar 1 from said main shaft, a looper cooperating with said. needles, means connected with said main shaft on said projecting arm for operating the looper, a fixed thread guide above the work support, 'a movable thread hook cocperating with said fixed'l'thread guide for forming a loop in the cross thread and positioning the same for the entrance of the needle farthest from the thread guide, and means connected to said main shaft in said arm for oscillating said thread hook.

2. The combination of a standard, an arm projecting therefrom, a depending support carried by said arm, a Work support suspended by said support and extending toward and terminating adjacent said standard, a main shaft extending through said standard and into said arm, a needle bar carried by said projecting arm, a plurality of needles mounted thereon, said needle bar being disposed so as to operate at the free end of said work supporting arm, means Within said arm for actuating the needle bar from said main shaft, a looper cooperating with said needles, means connected with said main shaft on said projecting arm for operating the looper, a fixed thread guide above the work support, a movable thread hook oooperating with said fixed thread guide for forming a loop in the cross thread and positioning the same for the entrance of the me dle farthest from the thread guide, a yoke supporting said-thread hook, and means connected to the main shaft on said projecting arm for oscillating said yoke. V

3. The combination of a standard, an arm projecting therefrom, a depending support carried by said arm, a work support suspended by said support and extending toward and terminating adjacent said standard, a main shaft extending through said standard and into said arm, a needle bar carried by said projecting arm, a plurality of needles mounted thereon, said needle bar being disposed so as to operate at the free end of said work supporting arm, means within said arm for actuating the needle bar from said main shaft, a looper cooperating with said needles, means connected with said main shaft on said projecting arm for operating the looper, a fixed thread guide above the work support, a movable thread hook cooperating with said fixed thread guide for forming a loop in the cross thread and positioning the same for the entrance of the needle farthest from the thread guide, a presser foot, a presser bar carrying said presser foot, said presser bar being mounted in said projecting arm, a yoke mounted to swing on the presser bar and carrying said thread hook, and means connected to the main shaft onsaid projecting arm for oscillating the yoke.

In testimony whereof, I affix my signature, in the presence of two witnesses.

SAMUEL GEORGE TATE.

Witnesses:

A. B. CLoTHInR, O. G. DOHSE. 

